The present invention relates to a method of manufacturing a color filter, and, although the invention is not so restricted, it relates more particularly to the manufacture of a color filter used for a liquid crystal color display and a colored scale of a video image camera.
The most convenient method of producing a color filter is by printing. However, printing has the problems that location during multicolor printing is difficult, and a high accuracy and a fine pattern cannot be achieved. A color filter having high accuracy and a very fine pattern, for use in a camera or the like, is therefore usually produced by photo-lithography. Although, however, photo-lithography provides a sufficiently high accuracy and fineness, a separate photo-lithographic process has to be carried our for each color, and this makes the manufacture extremely complicated. In addition, there is a limit to the size of the substrate that can be handled, due to limits imposed on devices such as an aligner.
Recently, a method of manufacturing a color filter has been developed by forming color layers by electrodeposition. The method is a very simple process and produces highly accurate patterns.
In a conventional color pattern manufacturing process using electric deposition, as shown in FIG. 4, a colored layer 3 (as shown in FIG. 4(b)) is formed by electric deposition over a conductive film 2 (as shown in FIG. 4(a)) having an arbitrary pattern. Next, a negative type photosensitive resin 7 having a black pigment dispersed therein is applied (as shown in FIG. 4(c)). The substrate has its back exposed (as shown in FIG. 4(c)) by using the colored layer as a photo mask. After a development (as shown in FIG. 4(d)), a transparent conductive film 4 is formed (as shown in FIG. 4(e)), and the photosensitive resin has a stripe shape (as shown in FIG. 4(f).
In the liquid crystal display of thin film transistor type expected in recent years to have a promising future, however, a shielding film is required to improve the shielding efficiency of the device so as to prevent optical leakage of a switching element. In order to improve the image quality, the shielding film is required to have a lattice-shaped pattern. In the existing manufacture process, however, the black pigment is dispersed in the resist so that its amount is limited and fails to provide the required shielding efficiency. Since, moreover, the shielding film is formed by the exposure of the substrate back using the colored layer as the mask, there arises a problem in that it is difficult to form the shielding film into the lattice shape.
It is, therefore, an object of the present invention to solve the above-specified problems of the prior art and to provide a process for manufacturing a multi-color pattern having a shielding film which has a high shielding efficiency and can be formed into an arbitrary pattern shape.